1. Field of the Invention
This invention refers to containers and more particularly to a container of steel concrete with a roof of sectorshaped prefabricated steel concrete components. Further the invention refers to a process for preparing such a container.
2. Description of the Prior Art
Large-scale containers of steel concrete are required for various purposes, particularly for storing drinking water, water for fire fighting, oil, fuel and other liquids as well as for the treatment of waste water and for storing granular material. Usually such containers are erected as a monolithic construction. In the case of small-scale containers, the usual flat roof may be provided. In the case of large scale containers, this mode of construction is not suitable.
So far in the case of large-scale containers, rooves with girders have been used. In both cases a plurality of supporting pillars have been necessary which must be distributed inside the container and which must be provided with foundations in the bottom plate. This mode of construction requires a large amount of concrete and steel and excessive manual labor. The erection of such a roof requires a scaffolding and form. The costs for the scaffolding and the form constitute a considerable part of the total costs for erecting the container. Further the container must have a cylindrical shape due to the high pressures. This geometry does not permit the erection of the roof in a series of individual sections and to, in this manner, lower the costs for the scaffolding and form.
Further it was attempted to lower the costs for the container roof by erecting a domed roof by assembled pre-cast, sectorshaped structural units. However, with this mode of construction, the container wall is subjected to a high tensile strain in the circumferential direction so that the costs for the reinforced container wall are increased. It has further been suggested to erect the container roof as a suspended roof with steel ropes on which concrete plates are layed. In such a roof the loads are carried merely by the ropes and therefore the roof is not very stable. Further the steel cables show a high thermal expansion so that the sealing of the joints is difficult.
Therefore a container has been suggested whereby merely a central support is provided and whereby the roof consists of beam-type, sector-shaped, precast steel concrete elements, which are supported by the container wall and the central support. Such a construction offers substantial economic advantages due to the avoidance of the costs for the scaffolding and form. It is however not suitable for erecting largescale containers since large amounts of material would be necessary for preparing the beam-type, precast components which are substantially only subject to bending strain.